In the manufacture of semiconductor devices and other products, ion implantation systems are used to impart impurities, known as dopant elements, into semiconductor workpieces, display panels, or other workpieces. Conventional ion implantation systems or ion implanters treat a workpiece with an ion beam in order to produce n- or p-type doped regions, or to form passivation layers in the workpiece. When used for doping semiconductors, the ion implantation system injects a selected ion species to produce the desired extrinsic material. For example, implanting ions generated from source materials such as antimony, arsenic, or phosphorus results in n-type extrinsic material workpieces. Alternatively, implanting ions generated from materials such as boron, gallium, or indium creates p-type extrinsic material portions in a semiconductor workpiece.
Conventional ion implantation systems include an ion source that ionizes a desired dopant element which is then accelerated to form an ion beam of prescribed energy. The ion beam is directed at a surface of the workpiece to implant the workpiece with the dopant element. The energetic ions of the ion beam penetrate the surface of the workpiece so that they are embedded into the crystalline lattice of the workpiece material to form a region of desired conductivity. The implantation process is typically performed in a high vacuum process chamber which prevents dispersion of the ion beam by collisions with residual gas molecules and which minimizes the risk of contamination of the workpiece by airborne particulates.
Conventionally, ion implantation processes are performed in either a batch process, wherein multiple substrates are processed simultaneously, or in a serial process, wherein a single substrate is individually processed. Traditional high-energy or high-current batch ion implanters, for example, are operable to achieve a short ion beam line, wherein a large number of workpieces may be placed on a wheel or disk, and the wheel is simultaneously spun and radially translated through the ion beam, thus exposing all of the substrates surface area to the beam at various times throughout the process. Processing batches of substrates in such a manner, however, generally makes the ion implanter substantially large in size.
In a typical serial process, on the other hand, an ion beam is either scanned in a single axis across a stationary workpiece, or the workpiece is translated in one direction past a fan-shaped, or scanned ion beam. The process of scanning or shaping a uniform ion beam, however, generally requires a complex and/or long beam line, which is generally undesirable at low energies. Furthermore, a uniform translation and/or rotation of either the ion beam or the workpiece is generally required in order to provide a uniform ion implantation across the workpiece. However, such a uniform translation and/or rotation can be difficult to achieve, due, at least in part, to substantial inertial forces associated with moving the conventional devices and scan mechanisms during processing.
Therefore, a need exists for a device for scanning an ion beam across a substrate, wherein the substrate is uniformly translated and/or rotated with respect to the ion beam, wherein the device has a relatively low inertia associated therewith.